Spionidae is a family of marine worms within the

Polychaeta Polychaeta () is a paraphyletic class of generally marine annelid worms, commonly called bristle worms or polychaetes (). Each body segment has a pair of fleshy protrusions called parapodia that bear many bristles, called chaetae, which are ...

. Spionids are selective deposit feeders that use their two grooved

palps Pedipalps (commonly shortened to palps or palpi) are the second pair of appendages of chelicerates The subphylum Chelicerata (from New Latin, , ) constitutes one of the major subdivisions of the phylum Arthropoda. It contains the sea spiders, ...

to locate prey. However, some spionids are capable of interface feeding, i.e. switching between deposit and suspension feeding. Spionids produce tubes by cementing sand grains and detritus material with mucus produced by their glandular pouches. The Spionidae is one of the most studied polychaete families given their biological and commercial importance. Members of this family have been used in regeneration studies and some are capable of boring into calcareous substrate which has destructive implications for commercially important shellfish.

References

Annelid families Canalipalpata {{annelid-stub